Pediatric White Blood Cell Disorders

Overview

White blood cells, also known as leukocytes, are generated by the body to help protect against bacterial, viral, and fungal infections. In general, the presence of too many or too few white blood cells in your child typically signals an imbalance.

• Low white blood cell count (leukopenia) occurs when there are too few leukocytes in the bloodstream. Persistent leukopenia can elevate the risk of infections and may result from various diseases and conditions.
• High white blood cell count (leukocytosis) refers to an excess of leukocytes in the blood, typically due to an infection. A range of diseases and conditions can lead to a prolonged increase in white blood cells.

White blood cells come in various varieties, and each one fights disease in a unique way. The primary kinds are:

• Neutrophils
• Lymphocytes
• Monocytes
• Eosinophils
• Basophils

Disorders of the white blood cells that affect a particular kind of white blood cell are as follows:

• Neutropenia: Neutropenia refers to a reduced number of neutrophils, a type of white blood cell that defends against bacterial and fungal infections. It can be caused by cancer or conditions that damage the bone marrow, as well as certain medications, diseases, or infections.
• Lymphocytopenia: Lymphocytopenia is the reduction of lymphocytes, a type of white blood cell that helps protect against viral infections. This condition can be inherited, associated with specific diseases, or triggered by medications or treatments.
• Monocyte disorders: Monocytes assist in removing dead or damaged tissue and help regulate the immune system. An increase in monocytes can result from infections, cancer, autoimmune diseases, or other conditions. A decrease can be caused by toxins, chemotherapy, and other factors.
• Eosinophilia: Eosinophilia is the presence of more eosinophil cells than normal, a type of white blood cell that fights disease. It is often triggered by allergic reactions or parasitic infections but can arise from various conditions.
• Basophilic disorders: Basophils make up a small fraction of white blood cells, but they play a role in wound healing, infections, and allergic responses. A lower basophil count can result from allergic reactions or infections, while a higher count may indicate certain blood cancers or other disorders.

Symptoms

The specific type of white blood cell disorder a child has will influence their symptoms. It’s essential to obtain an accurate diagnosis from your child’s doctor. Common signs of white blood cell issues may include:

• Mouth sores
• Skin abscesses
• Invasive fungal infections
• Severe gum disease (periodontal disease)
• Frequent infections, often affecting the sinuses, ears, or lungs

Certain conditions, such as leukocyte adhesion deficiency—which leads to delayed wound healing—and Shwachman-Diamond syndrome—which causes chronic, sometimes oily diarrhea—present unique symptoms.

Causes

White blood cell disorders can arise from either abnormal counts of white blood cells or dysfunctional white blood cells, with neutrophils and lymphocytes being the most common types affected.

Low white blood cell count

Neutropenia is a condition characterized by a low count of neutrophils in the blood, which can be either congenital (genetically inherited) or acquired (resulting from medications, toxins, viral infections, or an autoimmune response). Shwachman-Diamond syndrome is a rare genetic disorder marked by pancreatic dysfunction and congenital neutropenia, where neutrophils are produced in insufficient amounts. Kostmann syndrome, a more severe type of congenital neutropenia, results in a near absence of neutrophils due to improper maturation. Individuals with this condition frequently suffer from infections and mouth sores early in life.

High white blood cell count

Eosinophilia is an uncommon condition characterized by an elevated number of eosinophils in the blood, typically triggered by signals from other cells requesting increased eosinophil production. In contrast, neutrophilia refers to a higher than normal number of neutrophils in the blood, most often acquired in response to infections or medication. While infections and drugs are the primary causes, there are also some less common triggers.